Microtome

A microtome, comprising:

• a. a base having a unitary, rigid structure;
• b. a carriage for carrying an object, the carriage being mounted on the base for reciprocating horizontal movement;
• c. a completely closed, rectangular frame-like unit vertically movable relative to the base, comprising
• i. a knife holder having two ends;
• ii. two vertical columns having their upper ends rigidly secured to the respective ends of the knife holder;
• and
• iii. a horizontal bridge rigidly connecting the lower ends of the vertical columns below the carriage;
• d. a knife for cutting sections from the object, the knife being mounted substantially horizontally in the knife holder for vertical movement with the frame-like unit for adjusting the thickness of the sections to be cut;
• e. means surrounding the columns over a substantial part of their length provided in opposed walls of the base, for slidably guiding axial movement of the columns;
• f. centrally disposed crew means rotatably depending from the upper wall of the base below the carriage;
• g. a nut centrally disposed in the horizontal bridge cooperating with the screw means;
• h. the frame-like unit hanging from the screw means and being vertically adjustable by the screw means.